1. Technical Field
This disclosure relates generally to control of the motion of mobile components, relative to static components, based at least in part upon a linear actuator mechanism using Lorentz forces, also referred to herein as a Lorentz actuator mechanism.
2. Description of the Related Art
The advent of small, mobile multipurpose devices such as smartphones and tablet or pad devices has resulted in a need for high-resolution, small form factor cameras for integration in the devices. Some small form factor cameras may incorporate optical image stabilization (OIS) mechanisms that may sense and react to external excitation or disturbance by adjusting location of the optical lens on the X and/or Y axis in an attempt to compensate for unwanted motion of the lens.
Some small form factor cameras may incorporate an autofocus (AF) mechanism whereby the object focal distance can be adjusted to focus an object plane or field in front of the camera at an image plane to be captured by an image sensor (also referred to herein as a photosensor). In some such autofocus mechanisms, the optical lens is moved as a single rigid body along the optical axis (referred to as the Z axis) of the camera to refocus the camera. In addition, high image quality is easier to achieve in small form factor cameras if lens motion along the optical axis is accompanied by minimal parasitic motion in the other degrees of freedom, for example on the X and Y axes orthogonal to the optical (Z) axis of the camera. Thus, some small form factor cameras that include autofocus mechanisms may also incorporate optical image stabilization (OIS) mechanisms that may sense and react to external excitation or disturbance by adjusting location of the optical lens on the X and/or Y axis in an attempt to compensate for unwanted motion of the lens.
There is a strong desire, for a given size of camera, to fit bigger lenses and image sensors to improve image quality, and hence there is a desire to reduce the size of components such as actuator mechanisms. However, some small-sized components, including various components included in actuator mechanisms, can be relatively complex to assemble and can be vulnerable to failure, based at least in part upon small size and complexity of various components.
In addition, to implement adjustments of the location of the optical lens, for one or more of AF or OIS mechanisms, the position of the optical lens may need to be determined, and adjustments to the position (“displacements”) caused by commands to actuator mechanisms can be monitored, and the commands adjusted, in order to adjust the displacement of the optical lens as desired. As a result, in order to accurately control displacements of a mobile component in one or more various directions, such as accurately controlling displacement of an optical lens in a Z axis for autofocusing, controlling displacement of an optical lens in an X axis, Y axis, etc. for optical image stabilization, etc., it can be important for a device including an actuator mechanism configured to cause such displacement to accurately determine a displacement of the optical lens caused by commanded adjustments to the actuator mechanism.